What does the EVOH barrier do?
It blocks oxygen from diffusing through the pipe wall into the heating water. Dissolved oxygen corrodes steel boilers, manifolds, valves and radiators. Barrier (EVOH) grades are used in closed circuits containing metal parts; the two-layer non-barrier standard grades suit raw-water runs or all-plastic systems.
PE-RT vs PEX — which to choose?
PE-RT is not crosslinked, so it is softer, easier to lay, fully recyclable and heat-fusible, and is cost-effective for low-temperature underfloor heating up to about 70 °C. PEX is crosslinked for higher temperature and pressure but cannot be heat-fused. For warm-water UFH loops PE-RT/EVOH is usually the value choice; for hotter mains choose PEX-AL-PEX.
Pressure and temperature?
All listed PE-RT grades are rated PN6 and −20…+70 °C, designed for low-temperature hydronic underfloor heating rather than high-temperature radiator risers. If your duty exceeds this, use our PN16/PN20 PEX-AL-PEX multilayer pipe.
